A new study that claims to present evidence of alien life is being met with a healthy dose of skepticism in the scientific community.

On July 31, a team of British researchers sent a balloon into the stratosphere over England, where it collected samples at an altitude range of 14 miles to 17 miles (22 to 27 kilometers). The balloon's scientific payload returned to Earth toting the cell wall, or frustule, of a type of microscopic algae called a diatom, the scientists report in the Journal of Cosmology.

"Most people will assume that these biological particles must have just drifted up to the stratosphere from Earth, but it is generally accepted that a particle of the size found cannot be lifted from Earth to heights of, for example, 27 km. The only known exception is by a violent volcanic eruption, none of which occurred within three years of the sampling trip," lead author Milton Wainwright, of the University of Sheffield in the United Kingdom, said in a statement Thursday (Sept. 19).

"In the absence of a mechanism by which large particles like these can be transported to the stratosphere, we can only conclude that the biological entities originated from space," Wainwright added. "Our conclusion then is that life is continually arriving to Earth from space, life is not restricted to this planet and it almost certainly did not originate here."

The diatom fragment may have been delivered to Earth by a comet, Wainwright and his colleagues write in the paper, which can be read here at the Journal of Cosmology.

Extraordinary claims require extraordinary evidence

The idea that life is widespread throughout the universe and has been transported to many worlds by objects such as comets — a notion known as panspermia — is credible, at least over relatively short cosmic distances, said astronomer Seth Shostak of the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, Calif.

However, that doesn't necessarily mean the new study will stand up to the intense scientific scrutiny it's likely to receive, he said.

"In the past, most members of the astrobiology community have found it easier to ascribe these claims to terrestrial contamination than to extraterrestrial hitchhikers," Shostak told SPACE.com via email. "It remains to be seen whether that opinion will be changed by these new results." [10 Alien Encounters Debunked]

Indeed, other scientists said they would like to see more convincing evidence of a cosmic origin for the organism snagged by the balloon.

"There is probably truth to the report that they find curious stuff in the atmosphere," Chris McKay, an astrobiologist at NASA's Ames Research Center in Moffett Field, Calif., told SPACE.com via email. "The jump to the conclusion that it is alien life is a big jump and would require quite extraordinary proof. (The usual Sagan saying: extraordinary claims require extraordinary evidence.)"

McKay gave an example of what might constitute such extraordinary evidence.

"If they were able to show that it was composed of all D amino acids (proteins in Earth life are made of L amino acids), that would be pretty convincing to me," he said. "So some sort of biochemical indication that it does not share Earth biochemistry. If it does indeed share Earth biochemistry, proving that it is of alien origin is probably impossible."

Further study needed

Wainwright and his team plan to study their stratospheric samples further in an attempt to find a smoking gun for an off-Earth origin. For example, the researchers will analyze the ratios of various isotopes, which are varieties of an element that have different numbers of neutrons in their atomic nuclei.

"If the ratio of certain isotopes gives one number, then our organisms are from Earth; if it gives another, then they are from space," Wainwright said.

However, astrobiologist Dirk Schulze-Makuch of Washington State University thinks the study team should have performed such follow-up analyses, and consulted diatom experts, before publishing its provocative claim.

"Perhaps the fragment came actually from the stratosphere and is not contamination, but basing this conclusion only on one particle and very limited analysis seems quite odd to me and inferring an extraterrestrial origin completely off-base," Schulze-Makuch told SPACE.com via email.

Schulze-Makuch also thinks comets are unlikely incubators for life, suspecting that life first arose on a planetary body. And the presence of a diatom on a comet would be especially surprising, he said.

"Diatoms are actually relatively advanced life forms on Earth and developed most likely sometime at the beginning of the Mesozoic (probably Jurassic time period), thus very late during evolution (probably at least 3 billion years after the origin of life on Earth)," Schulze-Makuch said, adding that diatoms are typically aquatic and there is no liquid water on a comet, except during the brief periods when the icy objects approach the sun.

"Besides, I would expect an extraterrestrial organism or even remnant of an organism to be quite different from what we see on Earth in some significant ways (as the environment around it, its 'habitat,' will affect the form and function of the organism), and certainly not be linked to some kind of diatom species on Earth," Schulze-Makuch said.

That paper was not well received by outside scientists, some of whom questioned the journal's credibility as well.

"It isn't a real science journal at all, but is the ginned-up website of a small group of crank academics obsessed with the idea of [Fred] Hoyle and [Chandra] Wickramasinghe that life originated in outer space and simply rained down on Earth," P.Z. Myers, a biologist at the University of Minnesota, Morris, wrote on his popular science blog Pharyngula at the time.

Wickramasinghe is a co-author of the new stratospheric diatom paper, a fact that could color its reception in the wider scientific community.

"I don't have ANY expertise in this area," Rosie Redfield, a microbiologist at the University of British Columbia, told SPACE.com via email. Redfield was among the outspoken critics of the Journal of Cosmology's 2011 meteorite announcement. "But neither the Journal of Cosmology nor Dr. Wickramasinghe have any scientific credibility, and one fragment of a diatom frustule is hardly significant evidence."

Evidence is building that Earth life originated on Mars and was brought to this planet aboard a meteorite, said biochemist Steven Benner of The Westheimer Institute ...for Science and Technology in Florida.

An oxidized form of the element molybdenum, which may have been crucial to the origin of life, was likely available on the Red Planet's surface long ago, but unavailable on Earth, said Benner, who presented his findings today (Aug. 28; Aug. 29 local time) at the annual Goldschmidt geochemistry conference in Florence, Italy. [The Search for Life on Mars (Photo Timeline)]

"It’s only when molybdenum becomes highly oxidized that it is able to influence how early life formed," Benner said in a statement. "This form of molybdenum couldn’t have been available on Earth at the time life first began, because 3 billion years ago, the surface of the Earth had very little oxygen, but Mars did. It’s yet another piece of evidence which makes it more likely life came to Earth on a Martian meteorite, rather than starting on this planet."

Organic compounds are the building blocks of life, but they need a little help to make things happen. Simply adding energy such as heat or light turns a soup of organic molecules into a tarlike substance, Benner said.

That's where oxidized molybdenum comes in. Inserting it or boron, another element, into the mix would help organics make the leap to life, Benner added.

"Analysis of a Martian meteorite recently showed that there was boron on Mars; we now believe that the oxidized form of molybdenum was there, too," he said.

Another point in Mars' favor is the likelihood that the early Earth was completely covered by water while the ancient Red Planet had substantial dry areas, Benner said. All of this liquid would have made it difficult for boron, which is currently found only in extremely dry places, to form in high enough concentrations on Earth when life was first evolving.

Further, Benner added, water is corrosive to RNA, which most researchers think was the first genetic molecule (rather than DNA, which came later). it's much easier for rocks to travel from Mars to Earth than the other way around.

Wherever Earth life originated, Benner is glad it put down roots on our blue planet.

"It’s lucky that we ended up here nevertheless, as certainly Earth has been the better of the two planets for sustaining life," Benner said. "If our hypothetical Martian ancestors had remained on Mars, there might not have been a story to tell."

Warp-drive technology, a form of "faster than light" travel popularized by TV's "Star Trek," could be bolstered by the physics of quantum thrusters — another science-fic...tion idea made plausible by modern science.

NASA scientists are performing experiments that could help make warp drive a possibility sometime in the future from a lab built for the Apollo program at NASA's Johnson Space Center in Houston.

A warp-drive-enabled spacecraft would look like a football with two large rings fully encircling it. The rings would utilize an exotic form of matter to cause space-time to contract in front of and expand behind them. Harold "Sonny" White, a NASA physicist, is experimenting with these concepts on a smaller scale using a light-measuring device in the lab. [Warp Drives and Transporters: How 'Star Trek' Tech Works (Infographic)]

"We're looking for a change in path length of the photon on the interferometer, because that would be potential evidence that we're generating the effect we're looking for," White told SPACE.com. "We've seen, in a couple different experiments with several different analytic techniques, a change in optical-path length. We're making one leg of the interferometer seem a little shorter because of this device being on, versus the device being off. That doesn't mean that it's what we're looking for."

While these results are intriguing, they are in no way definitive proof that warp drive could work, White said. The scaled-down experiments are just a first step toward understanding if these concepts can be taken out of the realm of theory and applied practically.

Quantum thrust through space-time

Quantum-thruster physics, another technology White is looking into at NASA, could be the key to creating the fuel needed for a warp drive.

These electric "q-thrusters" work as a submarine does underwater, except they're in the vacuum of space, White told the crowd here at Starship Congress on Aug. 17. The spacecraft is theoretically propelled through space by stirring up the cosmic soup, causing quantum-level perturbations. The resulting thrust is similar to that created by a submersible moving through water.

"The physics models that tell us how to construct a q-thruster are the same models we'll use to generate, design and build a negative vacuum generator," White said. "The quantum thrusters might be a propulsion manifestation of the physics, like the big ring around the spacecraft. If you looked in there, there might be 10,000 of these little cans that are the negative vacuum generators."

White wants to try to apply the quantum-thruster physics models the researchers have been working with in the lab to their work with warp drive.

"We have measured a force in several test devices which is a consequence of perturbing the state of the quantum vacuum," White said. The effect has been small but significant in his experimentation. Going forward, White hopes to do more robust testing to possibly magnify those claims.

Do the time warp

The warp-drive ship itself would never be going faster than the speed of light, but the warped space-time around it could help the spacecraft achieve an effective speed of 10 times the speed of light within the confines of White's concept.

When first proposed by Mexican physicist Miguel Alcubierre in 1994, the warp drive would have required huge, unreasonable amounts of energy, but White's work brought those numbers down. Previous studies extrapolated that the drive would need energy equal to the mass energy of Jupiter.

"In the early epoch of the universe, there was a very short period known as inflation," said Richard Obousy, president of Icarus Interstellar. "We believe that during that inflationary period, space-time itself expanded at many times the speed of light, so there are tantalizing questions when you look at nature as a teacher. Is this something that can be duplicated around the vicinity of a spacecraft?"

Now, White thinks the drive could be powered by a collection of exotic mass about the size of NASA's Voyager 1 probe if the rings housing the mass were shaped